Page 17 - Pharmaceutical Organic Chemmistry-3 (Theoritical book) 24-25

Clinical Pharmacy PharmD - 2024/2025 Level 2 Pharmaceutical Organic Chemistry-3 (PC 305)
Part I

Chemistry of Heterocyclic compounds

What is meant by heterocyclic compounds?

Heterocyclic compounds are:

• Cyclic molecules with at least one atom other than carbon in the ring structure.

• Theoretically, any atom capable of forming at least two covalent bonds can be a

member of a heterocyclic ring.

• The most common hetero- atoms are nitrogen, oxygen and sulphur. Although

many others such as phosphorus, selenium and boron also exist.

N.B.

• Heterocyclic compounds include 3-, 4-, 5-, 6-, 7-, or 8-membered ring

compounds.

• They might contain one or more heteroatom in the ring.

• The heteroatoms might be similar or different, i.e., the ring may contain only
N, O, or S or a combination of these elements.

• In addition, heterocyclic compounds might exist as isolated systems or

condensed with other heterocyclic rings or with benzenoid compounds.